How to Cut Plans and Sections in Google SketchUp 8

In Google SketchUp, sections are objects that let you cut away parts of your model to look inside. You place sections wherever you need them, use them to create views you couldn’t otherwise get, and then delete them when you’re done.

The most common use for sections is to create straight-on, cut-through views of your model. These views often include dimensions and are typical of the drawings that architects make to design and explain space.

Straight-on, cut-through views are useful because they’re easy to read, you can take measurements from them (if they’re printed to scale), and they provide information that no other drawing type can.

The following terms can help you create different views of your model more easily:

Plan: A planimetric view, or plan, is a top-down, two-dimensional, nonperspectival view of an object or space. Put simply, it’s every drawing of a house floorplan you’ve ever seen. You generate a plan by cutting an imaginary horizontal slice through your model. Everything below the slice is visible, and everything above it isn’t.

Section: Not to be confused with sections, a sectional view, or section, is a from-the-side, two-dimensional, nonperspectival view of an object or space. You make a section by cutting an imaginary vertical slice through your model. Just like in a plan view, everything on one side of the slice is visible, and everything on the other side is hidden.

You cut plans and sections by adding section planes to your model. These are a little abstract because nothing like them exists in real life. In SketchUp, sectionplanes are objects that affect the visibility of certain parts of your model. When a section plane is active, everything in front of it is visible and everything behind is hidden. Everywhere a section plane cuts your model, a slightly thicker section cut line appears.

If you’re using Windows, open the Sections toolbar by choosing View, Toolbars, Sections. If you’re on a Mac, the Section Plane tool is in the Large Tool Set, which you can activate by choosing View, Tool Palettes, Large Tool Set. On both platforms, Section Plane looks like a white circle with letters and numbers in it.

To add a section plane, follow these steps:

Choose Tools, Section Plane to activate the Section Plane tool.

You can also activate Section Plane by choosing its icon from the Large Tool Set (Mac) or the Sections toolbar (Windows), if you have it open.

Move the Section Plane tool around your model.

Notice how the orientation of the Section Plane cursor (which is quite large) changes to be coplanar to whatever surface you hover over.

After you figure out where you want to cut, click once to add a section plane.

To create a plan view, add a horizontal section plane by clicking a horizontal plane like a floor. For a sectional view, add a vertical section plane by clicking a wall or other vertical surface. You can, of course, add section planes wherever you want; they don’t have to be aligned to horizontal or vertical planes.

Choose the Move tool.

Move the section plane you just added by clicking it once to pick it up and again to drop it.

You can only slide your section plane back and forth in two directions; SketchUp only allows section planes to move perpendicular to their cutting planes.

After you add a section plane and move it to the desired location, you can rotate and even copy it, just like any other object in your model. The section plane never affects your geometry — just the way you view it.

If you need to rotate your section plane, select it and use the Rotate tool.

In certain circumstances, rotating a section plane (instead of creating a brand-new one) can help explain a complex interior space.

To make a new section plane by copying an existing one, use the Move or Rotate tool to do it the same way you’d make a copy of any other SketchUp object.

Copying section planes is a great way to space them a known distance apart; this can be trickier if you use the Section Plane tool to keep adding new ones, instead.